PURPOSE: To reduce the phase drift of a PLL circuit to the temperature change.

CONSTITUTION: A PLL circuit secures the synchronization between the frequency of a voltage controlled oscillator and the frequency of an input signal. A phase control circuit of the PLL circuit inputs the output of a switching transistor TR 32 which performs the switching operations by the oscillation signal of the voltage controlled oscillator directly to an operational amplifier 36 constructing an integration circuit via the resistor dividing circuits 33 and 34. In such a constitution, the number of TRs can be decreased and also the phase drift can be reduced even to the temperature change for the PLL circuit.